4
 These barriers try to stop all pathogens therefore they are considered non- specific defences. The physical barriers of our general defence system consist of:  · The Skin- It is a physical barrier that stops pathogens.  · Clotting- If the skin is broken the blood clot stops entry of pathogens.  · Sebaceous and sweat glands- These produce chemicals that kill bacteria.  · Lysozyme- This is in the saliva and the tear glands. It kills bacteria.  · Mucous membranes- These secrete mucus which lines many body parts. The mucous traps pathogens and prevents them from entering the body.  · Nasal hairs- These remove suspended micro-organisms from the air.  · Cilia- These small hairs beat to force mucus to the pharynx for swallowing to the stomach. Coughing helps in this process.  · Hydrochloric acid- This is found in the stomach. It kills micro- organisms.  · The vagina- It contains bacteria that produce lactic acid that prevents the growth of pathogens. Also the vagina has a low pH to kill bacteria as well as mucous membranes. DON’T WRITE